ARRL has filed comments opposing an FCC proposal to delete the 3.3 – 3.5 GHz secondary amateur allocation. The comments, filed on February 21, are in response to an FCC Notice of Proposed Rulemaking () in WT Docket 19-348 in which the FCC put forward a plan to remove “existing non-federal secondary radiolocation and amateur allocations” in the 3.3 – 3.55 GHz band and relocate incumbent non-federal operations. The FCC’s proposal was in response to the MOBILE NOW [Making Opportunities for Broadband Investment and Limiting Excessive and Needless Obstacles to Wireless] Act, enacted in 2018 to make new spectrum available for mobile and fixed wireless broadband use. ARRL noted that amateur radio has a long history of successful coexistence with primary users of the band.

“There is no reason suggested by the Commission, or known to us, why the secondary status for amateur radio operations should not be continued for the indefinite future,” ARRL said in its comments. “We understand that secondary commercial users are less flexible than amateur radio users and may desire to relocate to protect continued provision of services and service quality. Radio amateurs, by contrast, benefit from having technical knowledge and no customer demands for continuous service quality, more flexibility to make adjustments, and often have the technical abilities necessary to design and implement the means to coexist compatibly with the signals of primary users.”

ARRL pointed to amateur radio’s “decades-long experience observing and experimenting with radiowave propagation” in the 3.3 – 3.5 GHz band that includes mesh networks, amateur television networks, weak signal long-distance communication, Earth-Moon-Earth (moonbounce) communication, beacons used for propagation study, and amateur satellite communications. In its comments, ARRL argued that it would be “premature” to remove the current secondary amateur radio allocation.

“This spectrum should not be removed from the amateur radio secondary allocation and left unused,” ARRL told the FCC. “Only at a later time may an informed assessment of sharing opportunities be made in the specific spectrum slated for re-allocation…. This depends upon the Congressionally-mandated NTIA studies of sharing or relocation options that have yet to be completed and, if all or part of this spectrum is re-allocated, the nature and location of buildout by the non-federal users.” The NTIA oversees spectrum allocated to federal government users. ARRL noted that radio amateurs have established extensive infrastructure for the current band and are engaged in construction and experimentation that includes innovative “mesh networks” and amateur television networks that can be deployed to support public service activities.

With the NTIA report addressing the 3.1 – 3.55 GHz spectrum not expected until late March, ARRL said, “we do not yet know how much spectrum below and above the amateur secondary allocation may be reallocated to non-federal users and what opportunities may exist or be developed to share [that] spectrum” with new primary users and systems.

“Even if suitable new spectrum could be found for the existing amateur uses — which is difficult before the spectrum musical chairs activity is concluded — the costs to radio amateurs would be significant and be borne with no countervailing public benefit,” ARRL told the FCC.

“If the advent of new primary licensees forecloses some types of secondary operations, the amateur community will reevaluate the situation when some certainty exists,” ARRL concluded.